A Polish man living in Germany went about his business for about five years without realising he had been shot in the head because he was drunk when it happened.

Police in the western city of Bochum said on Tuesday that doctors found a .22 calibre bullet in the back of his head after the man went to have what he thought was a cyst removed.

Presented with the 5.6mm projectile, the 35-year-old recalled he had received a blow to the head about midnight at a New Year's Eve party "in 2004 or 2005", but had forgotten about it because he had been "very drunk", a police spokesman said.

"He told us he remembered having a sore head, but that he wasn't really one for going to the doctor," the spokesman said.

The wound later healed around the bullet and it was not until the man decided to have the lump examined due to recurring pains that the discovery was made.

Police said they were not treating the incident as suspicious as the bullet might have got lodged in the man's head when a reveller fired a gun in celebration.

"It may have been a shot fired up in the air which entered his head on the way down," the spokesman said.

The resident of Herne, who has lived in Germany for several years, was expected to be released from hospital after the bullet was removed on Friday, police said.

"When a man lies, he murders some part of the world.
These are the pale deaths which men miscall their lives.
All this I cannot bear to witness any longer.
Cannot the Kingdom of Salvation take me home?"